Temperature monitor for electro-mechanical part

ABSTRACT

A temperature monitor includes a temperature sensor, a transmitter, and a controller. The temperature sensor generates a temperature signal based upon a detected temperature and the controller controls the temperature sensor to generate the temperature signal and controls the transmitter to transmit the temperature signal along with a time at a first predetermined interval.

This application is based on Japanese patent application No.2000-398294,the entire contents of which are incorporated herein by reference.

TECHNICAL FIELD

This invention relates to a temperature monitoring system for electricpower-applied section and particularly to a temperature monitoringsystem for electric power-applied section that can safely and easilymonitor the temperature change of electric power-applied section withoutincurring an accident such as electric shock.

BACKGROUND ART

Conventionally, to main circuit connection of transformer station andelectric power-applied section of high-voltage cable, a thermo-sensinglabel is attached such that its color changes to indicate that a stateof exceeding a predetermined temperature continues for a certain periodfor the purpose of constantly supplying electric power, thereby allowingthe maintenance worker to visually monitor it.

FIGS. 1( a) to (c) show a conventional structure for supporting thetransmission line at a power transmission tower. FIG. 1( a) shows aschematic composition of the power transmission tower. FIG. 1( b) showsa support portion for the transmission line. The power transmissiontower 2 is composed of cable supporting portions 2A to support thetransmission lines 3A, 3B and 3C, and insulators 8 that are connected tothe top of the cable supporting portions 2A to suspend the transmissionlines 3A, 3B and 3C while insulating from the lines. The cable clamp 7attached to each of the transmission lines 3A, 3B and 3C is fixed to theinsulator 8 to support each of the transmission lines 3A, 3B and 3C. Thethermo-sensing label is attached on the surface of the cable clamp 7.

FIG. (c) shows the thermo-sensing label 10, which includes a temperatureindicating section 10A that is of a thermo-sensitive material whosecolor changes according to temperature, and temperature index sections10B (red[higher than 65° C.]) and 10C (yellow[higher than 50° C.]) thatindicate the relation of color indicated by the temperature indicatingsection 10A and the temperature. The temperature indicating section 10Ahas irreversibility that the state of having the color once changed isretained. For example, when the temperature of cable clamp 7 is kepthigher than 65° C. for a certain time due to electrical overload, itscolor changes to red and after that the color changing state isretained. Therefore, when it is found in the maintenance check that thethermo-sensing label 10 has the color changed, it can be visually andeasily checked that the cable clamp 7 reached a high temperature. Anincrease in temperature of the cable clamp 7 can be caused by loosing ofa bolt, deterioration of a cable, increasing of load due to an increasein amount of current carried.

Japanese patent application laid-open No.5-66714 discloses athermo-sensing label that has a temperature indicating section of athermo-sensitive material with reversibility. In the thermo-sensinglabel, the transparency of the thermo-sensitive material varies betweentransparent and white opaque depending on temperature, and thethermo-sensitive material has reversibility in transparency. Therefore,the thermo-sensing label can be used repeatedly.

However, in the conventional temperature monitoring system using thethermo-sensing label, there is a problem that even when a periodicaltemperature change not reaching the extraordinary temperature occurs atthe electric power-applied section due to an increase in amount ofcurrent carried, it cannot be detected since the system is designed todetect that its-monitored object reaches an extraordinary temperature.

Also, in the conventional temperature monitoring system, it is necessaryto visually check the color change of temperature indicating section.Therefore, in such a place that cannot be easily accessed by themaintenance worker for safety reasons, the object to be monitored willbe subject to limitations. When remote monitoring by a camera etc. isemployed instead of visually checking, it will be costly.

It is an object of the invention to provide a temperature monitoringsystem for electric power-applied section that can safely and at lowcost monitor a temperature change of electric power-applied sectionwithout having a monitored object limited and obtain a temperaturehistory record according to a situation of monitored object.

DISCLOSUR OF INVENTION

According to the invention, a temperature recording device having amemory to store a temperature record based on measurements oftemperature sensor is attached to an electric power-applied section,e.g., main circuit connection or high-voltage cable. This temperaturerecording device conducts a measurement of temperature at predeterminedintervals and transmits, at predetermined intervals, a temperaturerecord obtained by the measurement through wireless communication to amonitoring device. Thus, it can be rapidly detected that the electricpower-applied section reaches an extraordinary temperature.

BRIEF DESCRIPTION OF DRAWINGS

FIGS. 1( a) to (c) show a schematic composition of conventionaltemperature monitoring system for electric power-applied section.

FIGS. 2( a) and (b) show a schematic composition of temperaturemonitoring system for electric power-applied section in a preferredembodiment of the invention.

FIGS. 3( a) and (b) are enlarged views showing the installation of atemperature monitor 5A in a preferred embodiment of the invention.

FIG. 4( a) is a broken top view showing the temperature monitor 5A inthe preferred embodiment of the invention.

FIG. 4( b) is a cross sectional view cut along the line b—b in FIG. 4(a).

FIG. 5( a) is a perspective view showing a temperature history recordingunit 40 in the preferred embodiment of the invention.

FIG. 5( b) is a cross sectional view showing the temperature historyrecording unit 40 in FIG. 5( a).

FIG. 6 is a circuit diagram, showing the temperature history recordingunit 40 in the preferred embodiment of the invention.

FIG. 7 is a circuit diagram showing a memory 407 of the temperaturehistory recording unit 40 in the preferred embodiment of the invention.

FIG. 8( a) is a control block diagram showing the temperature monitor 5Ain the preferred embodiment of the invention.

FIG. 8( b) illustrates a signal transmission system between thetemperature monitor 5A and a monitoring device 101 in the preferredembodiment of the invention.

FIG. 9( a) illustrates a transmit request operation from a receivingunit 90 in the preferred embodiment of the invention.

FIG. 9( b) illustrates a transmit operation of temperature historyrecord from the respective temperature monitors 5A to 5F in thepreferred embodiment of the invention.

BEST MODE FOR CARRYING OUT THE INVENTION

Temperature monitoring system for electric power-applied section of theinvention is explained below in reference to the drawings.

FIG. 2 shows an electric power-applied section in a preferred embodimentof the invention, FIG. 2( a) shows the schematic composition of a powertransmission system, and FIG. 2( b) is an enlarged view showing atemperature monitor 5A installed on a power transmission line 3A. Thepower transmission system includes: a transformer station 1 thatsupplies electric power; power transmission lines 3A, 3B and 3C that arewired through a power transmission tower 2; an optical ground wire(OPGW) 100B, insulators 8 that suspend the power transmission lines 3A,3B and 3C to the power transmission tower 2 while insulating them fromthe tower; temperature monitors 5A, 5B, 5C, 5D, 5E and 5F that areinstalled on the power transmission lines 3A, 3B and 3C to detect thetemperature, recording it as a record of temperature history(hereinafter referred to as “temperature history record”) as well as itsmeasurement time to a temperature history recording section describedlater and sending the temperature history record through radio wave; areceiving unit 90 that communicates through radio wave with thetemperature monitors 5A, 5B, 5C, 5D, 5E and 5F; a signal line 100A thatconnects the OPGW 100B to the receiving unit 90; and a monitoring device101 that analyzes the temperature of power transmission lines 3A, 3B and3C based on the temperature history record to be inputted through theOPGW 100B.

The temperature monitor 5A is attached through an attachment 5 a to acable clamp 7 to suspend the power transmission line 3A to the powertransmission tower 2. The cable clamp 7 is supported, through theinsulator 8 connected to an insulator connecting portion 7A, by a cablesupporting portion 2A of the power transmission tower 2. The othertemperature monitors 5B, 5C, 5D, 5E and 5F are, in like manner, attachedto the power transmission lines 3A, 3B and 3C.

FIG. 3 is an enlarged view of the cable clamp 7, where (a) is viewedfrom the side and (b) is viewed in the longitudinal direction of thepower transmission line 3A. The cable clamp 7 is fixed to the powertransmission line 3A by fastening clamp members 7B and 7C, which are ofmetal such as aluminum, by bolts 7D, nuts 7E, spring washers 7F andwashers 7G. The attachment 5 a fixes the temperature monitor 5A onto theperiphery of the cable clamp 7 by using bolts 5 b, nuts 5 c and washers5 d.

FIG. 4 is an enlarged view of the temperature monitor 5A, where (a)shows its internal structure viewed from the top and (b) shows theinternal structure cut along the line b—b in (a). In this embodiment,only the temperature monitor 5A is explained below, while the othertemperature monitors 5B, 5C, 5D, 5E and 5F have the same structure as5A. Meanwhile, for convenience of explanation, FIG. 4( a) shows awatertight section 50D with the top being opened, although it exactlyaccommodates a wireless communication section etc.

The temperature monitor 5A is composed of a base 50A of ABS resin havinggood heating resistance and low-temperature resistance, and a protectivecase 50B. The base 50A has a groove 50C to engage the attachment 5 a(not shown) when it is secured to the cable clamp 7, and it isintegrated with the protective case 50B by being screwed up thereto toform the watertight section 50D inside them. A sealing member 52 toprevent water etc. from invading the watertight section 50D is insertedto the junction between the base 50A and the protective case 50B.

Included in the watertight section 50D are: a lithium battery 110 aspower source; the wireless communication section 60 on whichsemiconductor circuit units for conducting the temperature historyrecording operation and the wireless communication with outside aremounted, its substrate surface being positioned in the directionvertical to the power supplying direction; a conductive member 53 thatelectrically connects the wireless communication section to the negativeelectrode of the lithium battery 110; a conductive member 54 thatelectrically connects the wireless communication section to the positiveelectrode of the lithium battery 110; a supporting member 55 thatsecures the conductive member 53 inside the watertight section 50D; aseparating member 57 that supports the conductive member 53 and a groundterminal 59 to isolate them each other; and a sealing member 56 thatprevents water from invading the watertight section 50D through theseparating member 57. The conductive member 54 is positioned by asupporting member 52 such that it contacts the positive electrode of thebattery 110.

The wireless communication section 60 includes: a semiconductor device61 for wireless communication operation; a substrate 62 on which awiring pattern is formed, the substrate serving to transmit/receiveradio wave as an antenna in the wireless communication operation; asemiconductor device (power supplying unit) 70 that controls powersupplied to the wireless communication section 60; and a semiconductordevice (main controller) 80 that controls the temperature historyrecording operation and the wireless communication with outside. Thewireless communication section 60 is positioned by the supporting member52 such that it vertically stands in the watertight section 50D.

The base 50A accommodates detachably a temperature history recordingunit 40 that includes lithium battery 44, a semiconductor chip 45, acircuit board 47 etc. in an opening at the bottom. The temperaturehistory recording unit 40 is electrically connected to the wirelesscommunication section 60 being inside the watertight section 50D througha spring-shaped signal input/output terminal 58 and the ground terminal59 provided in the opening. Furthermore, an insulating member 48 of amaterial such as silicon with good thermal conductivity is insertedbetween the temperature history recording unit 40 and the cable clamp 7.In this embodiment, the dimension of the protective case 50B is 35 mm inwidth, 35 mm in depth and 20 mm in height.

FIGS. 5( a) and (b) show the temperature history recording unit 40. Thetemperature history recording unit 40 is called “button-type coolmemory” which is a product being merchandised by the applicant. Thetemperature history recording unit 40 includes: outside its metal caseof stainless etc., a signal input/output section 41 at the top; acylindrical ground terminal 42 at the side; and a flange 43 composing athermometric surface at the bottom; and inside the metal case, thelithium battery 44 that supplies power to the circuits; thesemiconductor chip 45 that includes a temperature sensor to detecttemperature; and the circuit board 47 that has the semiconductor chip 45fixedly mounted thereon with a bump 46 of solder etc. The circuitpattern forming surface of the semiconductor chip 45 is placed facingthe circuit board 47.

The temperature sensor uses a PN-junction type diode for temperaturedetection, which detects the temperature of cable clamp 7 based on acomparison between the forward voltage and the reference voltage. Asealing member 49 is provided between the signal input/output section 41and the ground terminal 42 to give a watertight structure. Also, aspacer (not shown) of resin is provided inside the metal case to fillthe interior space. The outer diameter of the temperature historyrecording unit 40 is about 17 mm.

FIG. 6 shows a circuit composition of the temperature history recordingunit 40. It is composed of: a clock controller 402 that controls a clockfunction inside the circuit based on a reference clock outputted from anoscillator 401; a register 403 that temporarily stores clock dataoutputted from the clock controller 402; an ID section 404 that stores64-bit serial number uniquely assigned to the temperature historyrecording unit 40; an interface (I/F) section 405 that controls the datainput/output between the wireless communication section 60 and the maincontroller 80; a power source 406, such as a lithium battery, thatsupplies power to the circuit; a memory 407 that stores various programsfor temperature history recording operation, temperature history recordoutputting operation etc. and arbitrary data; a temperature sensor 408that outputs a temperature detection signal according to temperature; ameasurement controller 409 that outputs A/D converted temperaturedetection signal together with the output of the clock controller 402 tothe memory 407; a temperature recording controller 410 that controls therespective sections, and an internal bus 411 that gives connectionsbetween the above components.

FIG. 7 shows a composition of the memory 407. It is composed of: atemperature alarming memory 412 that stores temperature and measurementtime, as a temperature alarming record, when the cable clamp 7 reaches ahigh temperature exceeding a permissible temperature range; a historymemory 413 that stores, as a history, a temperature record based onconditions of temperature measurement, other data and measurements oftemperature to be inputted at predetermined measurement intervals fromthe start of measurement; a program memory 414 that stores variousprograms; and a memory controller 415 that controls the writing andreading into/from the respective memories. If the history memory 413lacks a memory area due to the accumulation of temperature historyrecord data etc., then the storing of temperature data is stopped bymeans of the conditions of measurement or oldest data is deleted andlatest data is stored.

FIG. 8( a) shows controlling blocks of the temperature monitor 5A wherethe main controller 80 controls the temperature history recording unit40, wireless communication section 60 and power supplying section 70.

The main controller 80 includes an interface (I/F) (not shown), by whichit can be connected to a terminal device such as personal computer towhich data necessary to the initial setting etc. are inputted. Also,according to a read request signal inputted to the terminal device, atemperature history recording data are outputted from the temperaturehistory recording unit 40.

The power supplying section 70 supplies suitable power from a battery110 according to a power supply signal outputted from the maincontroller 80 in temperature recording operation, communicationoperation and non-operating standby. Also, it outputs the value ofremaining power of the battery when the main controller 80 requests tosend the remaining power of the battery 110.

The temperature history recording unit 40 conducts temperature recodingand temperature history recording based on initial setting, e.g. ameasurement time interval, temperature alarm setting by which atemperature history when sensing extraordinary heating is stored as atemperature alarm record, and a time period not to conduct thetemperature measurement, to be inputted by the terminal device beingconnected through the interface to the main controller 80 before beinglocally installed. Also, it outputs a transmit request signal fortemperature alarm record to the main controller 80 when getting thetemperature alarm record of the cable clamp 7.

FIG. 8( b) shows a signal transmission system between the temperaturemonitor 5A and the external monitoring device 101. The temperaturemonitor 5A encodes the temperature history record data obtained based onthe measurement of temperature at the cable clamp 7, and then transmitsit to a receiving unit 90 placed near a switch using radio wave in afrequency band of 315 MHz.

The receiving unit 90 electro-optically converts the receivedtemperature history recording data and transmits it through an opticalfiber 100 to the monitoring device 101. The monitoring device 101 is,for example, a personal computer equipped with a keyboard, a recordingmedium, a display, CD-ROM etc. and analyzes the transmitted temperaturehistory recoding data to get a temperature of the cable clamp 7, ameasurement time, and a temperature change.

On the other hand, the setting of temperature history recordingoperation can be, if necessary, changed by transmitting a signal forvarious setting values from the monitoring device 101 to the receivingunit 90 and then wirelessly transmitting the setting value from thereceiving unit 90 to the temperature monitor 5A. Although in FIG. 8( b)the receiving unit 90 is shown such that it wirelessly communicates withthe single temperature monitor 5A, it may wirelessly communicate withmultiple temperature monitors 5A.

The operation of the temperature monitoring system for electricpower-applied section of the invention is explained below in referenceto the drawings.

[1] Input of Initial Setting Values

An operator conducts the input operation while connecting the terminaldevice through the interface to the main controller 80 of thetemperature monitor 5A to initialize the temperature monitor 5A. Theinitializing operation can be conducted by, e.g., the monitoring device101. In initializing, the main controller 80 reads a serial numberstored in the ID section 404 of the temperature history recording unit40. After the initializing, the terminal device is used to input theinitial setting values of: an alarm temperature at the temperaturehistory recording unit 40; a first measurement interval (e.g., one hour)in normal operation; a time period of measurement; conditions of alarmtemperature (e.g., higher than 50° C., lower than −1° C.), acommunication interval with the receiving unit 90 (e.g., once a half aday); a communication protocol etc. Also, the linkage to an ID uniquelyassigned to the receiving unit 90 to be communicated with is set up. Themain controller 80 stores these initial setting values to the built-inmemory (not shown).

After the initial setting, an on-site worker attaches the insulatingmember 48 to thermometric surface of the temperature history recordingunit 40 by using an adhesive etc. Then, the worker places thetemperature monitor 5A on the surface of the cable clamp 7. He positionsit such that the insulating member 48 equally contacts the surface ofthe cable clamp 7, then fixing the temperature monitor 5A thereto byusing the attachment 5 a. The on-site worker, after completing theinstalling work, requests a test communication to an operator to operatethe monitoring device 101, so that a serial number request signal isoutputted from the monitoring device 101. The receiving unit 90transmits radio wave based on the serial number request signal to besent through the optical fiber 100 from the monitoring device 101. Whenthe main controller 80 receives the serial number request signal, itreads out the serial number stored in the memory and then transmits itto the receiving unit 90. The receiving unit 90 receives radio wavebased on the received serial number and electro-optically converts it,and then sends it through the optical fiber to the monitoring device101. The operator confirms whether or not the serial number received bythe monitoring device 101 corresponds to the temperature monitor 5A tobe communicated with. Thus, by communicating with the monitoring device101, it is confirmed whether or not the interference and communicationtrouble occur.

[2] Temperature History Recoding Operation

The temperature history recording unit 40 conducts the measurement oftemperature at the cable clamp 7 at first time intervals based on theinitial setting value. The temperature history recording unit 40 detectsthe temperature of the cable clamp 7 to be conducted from the surface ofthe cable clamp 7 through the insulating member 48 to the thermometricsurface of the temperature history recording unit 40 by the temperaturesensor 408. The temperature detected is converted to an electricalsignal according to the temperature by the measurement controller 409and sequentially stored into the history memory 413 of the memory 407.The time data to be outputted from the clock controller 402 issimultaneously stored as the measurement time. The power supplyingsection 70 supplies power needed to conduct the measuring and recordingoperations of temperature and, after completing these operations,supplies power in the standby mode with a small consumption power fromthe battery 110.

[3] Transmission of Temperature History Record

The main controller 80 controls the wireless communication section 60 tosend the temperature history record to the receiving unit 90 atcommunication intervals according to the initial setting value. In thewireless communication, the serial number of the temperature historyrecording unit 40 is sent to the receiving unit 90. Subsequently, thetemperature history record being stored in the history memory 413 issequentially sent through radio wave. The receiving unit 90electro-optically converts the received wave based on the temperaturehistory record, sending its signal light through the optical fiber cable100 to the monitoring device 101. The monitoring device 101photo-electrically converts the received signal light to analyze thetemperature history record.

FIGS. 9( a) and (b) show the communication operation between thereceiving unit 90 and the temperature monitors 5A, 5B, 5C, 5D, 5E and5F.

FIG. 9( a) shows the transmit request operation from the receiving unit90. The receiving unit 90 photo-electrically converts the light signalreceived through the optical fiber cables 100A and 100B, sending itthrough radio wave.

FIG. 9( b) shows the transmit operation of temperature history recordfrom the respective temperature monitors. The main controller 80 of therespective temperature monitors requests the temperature historyrecording unit 40 to output the temperature history record according tothe transmit request signal to be sent from the wireless communicationsection 60. The temperature history record is transmitted through radiowave to the receiving unit 90 in the order shown in FIG. 9( b). Thereceiving unit 90 electro-optically converts the received radio waveinto signal light, sending it through the optical fiber cables 100A and100B to the monitoring device 101. The monitoring device 101 receivesthe signal light and photo-electrically converts it, thereby analyzingthe temperature history record concerning the cable clamp 7.

[4] Transmission of Temperature Alarm Record

When the cable clamp 7 reaches a high temperature exceeding apermissible temperature range, the temperature history recording unit 40stores that temperature and measurement time as a temperature alarmrecord into the temperature alarm memory 421 of the memory 407 andoutputs a transmit request signal of temperature alarm record to themain controller 80. The main controller 80 controls the wirelesscommunication section 60 according to the transmit request signal tosend the temperature alarm record to the receiving unit 90.

Functions and effects obtained in the abovementioned embodiment of theinvention are as follows.

-   (1) The lithium battery 110, wireless communication section 60,    power supplying section etc. are housed in the protective case 50B    of the temperature monitor 5A. Therefore, the temperature of cable    clamp 7 can be accurately recorded without being influenced by an    environment change such as temperature and humidity.-   (2) In attaching the temperature monitor 5A to the cable clamp 7,    the thermometric surface of the temperature history recording unit    40 only has to be in contact with the measured object. Therefore,    another fixing member (e.g., a simple fixing member such as adhesive    tape) other than the attachment 5 a may be used. Furthermore, a    fixing means using adhesion and magnetic force may be employed. The    work time and cost required for the fixing can be reduced.-   (3) The temperature history recording unit 40 is installed through    the opening formed at the bottom of the temperature monitor 5A.    Also, the thermometric surface of the temperature history recording    unit 40 securely contacts the cable clamp 7 by means of the spring    force of signal input/output terminal 58 and ground terminal 59.    Therefore, even when a low-frequency vibration occurs due to AC    power transmission, a stable detection of temperature can be    performed since the thermometric surface of the temperature history    recording unit 40 securely contacts the surface of cable clamp 7.-   (4) The temperature and measurement time regarding the cable clamp 7    are in time-series stored in the memory 407 of the temperature    history recording unit 40. When the temperature alarm record is    obtained, it is rapidly transmitted to the receiving unit 90. Thus,    the occurrence of extraordinary temperature in the cable clamp 7 can    be rapidly known on the monitor side. On the other hand, when the    temperature of cable clamp 7 is in the normal range of temperature,    the transmit cycles of temperature history record to the receiving    unit 90 may be once a day or so. In this case, the consumed power    can be reduced.-   (5) The insulating member 48 with an excellent thermal conductivity    is laid between the temperature history recording unit 40 and the    cable clamp 7. Thus, temperature can be equally conducted from the    cable clamp 7 to the thermometric surface of the temperature history    recording unit 40. This prevents an inaccuracy in temperature    detection from occurring due to the dispersion of temperature on the    thermometric surface. Furthermore, the direct contact between the    temperature history recording unit 40 and the cable clamp 7 can    prevent a corrosion due to voltage difference. The insulating member    48 may be of film type to be adhered by adhesive etc. or paste type.-   (6) With respect to the wireless communication section 60 being    housed in the protective case 50B of the temperature monitor 5A, the    surface of substrate 62 is placed in the direction vertical to the    power supplying direction. This prevents a voltage difference from    occurring on the same substrate under high-field conditions.    Therefore, noise to be superposed in transmitting the temperature    history record data can be suppressed. This stabilizes the wireless    communication of temperature history record as well as enhancing the    reliability of wireless communication.-   (7) Due to employing the semiconductor type temperature sensor in    the temperature history recording unit 40, the consumed power    required to measure the temperature can be reduced. The life of    battery as power source can be extended that much. Also, the device    size can be reduced since a smaller battery is available. When the    consumption of battery is remarkable, it is assumed that there is a    significant increase in temperature at a position where the    temperature monitor is placed due to some trouble of the section    with cable clamp attached or power transmission line. In this case,    it is desirable to conduct the maintenance check as soon as    possible.

In the above embodiment, the temperature history record is outputtedfrom the temperature monitor 5A by means of transmitting it throughradio wave. Alternatively, the temperature monitor 5A may be removedfrom the electric power-applied section and then connected to a readdevice (not shown), thereby outputting the temperature history recordthrough the interface 405 to an external device. In this case, themonitoring of temperature can be continued for a long time since thepower of battery is not consumed for wireless communication.

Furthermore, in the embodiment of the invention, the temperature monitoris used to measure the temperature of cable clamp. It may be used tomeasure the temperature of a switch or bus bar in DC transformerstation, main circuit connection of transformer station etc.,non-conductive member such as insulator.

As described above, in the temperature monitoring system of theinvention, the temperature history based on the temperature andmeasurement time of electric power-applied section is recorded by thetemperature history recoding means. Therefore, the temperature historycan be obtained according to the situation of a measured object. Themonitoring of temperature can be thus conducted safely and not costlywithout limiting the measured object.

INDUSTRIAL APPLICABILITY

The temperature monitoring system of the invention is suitable to beused for such a measured object that the on-site worker is subjected toa danger or difficulty in monitoring the temperature due to highaltitude, high voltage and high field.

1. A temperature monitoring system for an electric power-appliedsection, comprising: a temperature history recording means for measuringa temperature of said electric power-applied section and recording saidtemperature as a temperature history together with its measurement time;and a control means for controlling the recording and a transmittingoperation of said temperature history at a first predetermined interval,wherein said temperature history recording means comprises: atemperature sensor that generates a temperature detection signalaccording to said temperature; a memory that stores, as said temperaturehistory, a measured temperature and a measurement time based on saidtemperature detection signal; and a housing comprising a watertightcircuit housing portion being formed to make a thermometric surface ofsaid temperature sensor contact a measured object, wherein said memorycomprises: a history memory that stores, in a time series, saidtemperature history; and a temperature alarm memory that stores, in atime series, as a temperature alarm, a temperature history being out ofa range of a normal temperature, and wherein: said control meanscontrols said temperature history recording means to conduct a recordingoperation of the temperature history at a second predetermined timeinterval that is shorter than said first predetermined time intervalwhen a temperature history is stored in said temperature alarm memory.2. A temperature monitor comprising: a temperature sensor that generatesa temperature signal based upon a detected temperature; a transmitter;and a controller that controls the temperature sensor to generate saidtemperature signal and that controls said transmitter to transmit saidtemperature signal along with a time signal at a first predeterminedinterval, wherein said controller controls said transmitter to transmitsaid temperature signal and said time signal at a second predeterminedtime interval that is shorter than said first predetermined interval ifsaid temperature signal indicates that said detected temperature isoutside of a predetermined temperature range.
 3. The monitor of claim 2,wherein the controller controls said transmitter to further transmit atemperature alarm signal if said temperature signal indicates that saiddetected temperature is outside of a predetermined temperature range.